Electric connector having jaws to receive a contact blade



May 31, 1955 E. G. JOHANSSON 9 ELECTRIC CONNECTOR HAVING JAWS TO RECEIVE A comm BLADE Filed May 27. 1950 Trac e/afar rrzeii' 6. Wham 930m United States Patent ELECTRIC CONNECTOR HAVING JAWS TO RECEIVE A CONTACT BLADE Ernest G. .lohansson, Belmont, Mass., assignor to Anchor Manufacturing Company, Boston, Mass., a corporation of Massachusetts Application May 27, 1950, Serial No. 164,788

1 Claim. (Cl. 339256) amount of heat is generated. This heat must be dis-' sipated through the meter blades and the jaw terminals or sockets of the meter base, thus requiring that the socket and terminals be of large cross section for good conductivity. Jaw terminals of large mass are also adblade switches and fuses.

Notwithstanding the desirability of jaws having large cross section, hitherto such jaws have been found to be too stiff to allow easy entry of the knife blade, while if the jaws are weakened they become distorted and fail to make good contact.

One object of the present invention is to provide a jaw terminal of the required mass and conductive characteristic which will receive standard knife blades easily without undue force being applied to the device carrying the blade. Further objects are to provide a socket and terminal which is of improved structure, being resistant to distortion, low in internal resistance, and simple and economical to manufacture.

In one aspect the present invention comprises'a socket having opposed jaw members for receiving the contact element, and including a backing member opposed to one of the jaw members, the other of the jaw members being flexibly mounted between the backing and other jaw and having a free end spaced from the backing member so as to make a yielding engagement with the backing member after a contact element is started between the jaws so that pressure on said contact element is increased after said engagement, the backing member and flexible jaw member in combination providing a path of increased across section while the flexible jaw allows the contact element to be easily started in the socket. Preferably one of the jaws is stiff and relatively of large cross section to afford good conductivity while said flexible jaw is of less cross section than the stiff jaw to afford greater flexibility, the combined cross sections of the flexible jaw and the backing member affording a conductive path at least substantially equal to that of the stiff jaw.

In a further aspect the flexible jaw member and the backing member are integrally formed in a U-shaped unit adapted to be mounted in a fixed position relative to the first jaw member, the flexible jaw and backing respectively constituting the legs of the U-shaped unit. Preferably a portion of one of the legs of the U-shaped unit extends towards the other leg.

In a further aspect the socket comprises a U-shaped ice body member, one leg of which constitutes the first of the aforesaid jaw members and the other leg of which constitutes a backing, with an insert unit mounted in the U-shaped body member, the insert unit including the aforesaid flexible jaw. Preferably the insert unit is also U-shaped with two legs as described above. If desired, the jaw leg of the body member and the insert unit are longer than the other leg of said members.

In a still further aspect the U-shaped body member has an extension laterally thereof and carries clamping means bridging said extension for clamping a conductor against said extension, the extension being an integral part of the U-shaped body member so as to afford a direct path from said conductor to the jaw member of the body member.

For the purpose of illustration typical embodiments of the invention are illustrated in the accompanying drawings in which Fig. l is an isometric view of a socket;

Fig. 2 is an end elevation of the socket;

Fig. 3 is an elevation from the opposite end of the socket;

Fig. 4 is an end elevation like Fig. 2 with a blade inserted in the socket;

Fig. 5 is an end elevation of another application of the socket;

Fig. 6 is a plan view of the socket shown in Fig. 5; and

Fig. 7 is an end elevation of a further embodiment of the socket.

One embodiment of the invention chosenfor the purvantageous with other heavy duty devices Such as k if pose of illustration and shown in Figs. 1 to 4 includes a U-shaped terminal body 1 formed of heavy sheet copper, and a U-shaped insert 2 formed of sheet copper approximately one-half the thickness of the body member. The U-shaped terminal body 1 is mounted on an insulating block 3 and includes a stiff jaw 4 on one leg of the U, and

a shortened backing 6 on the other leg of the U. Extending laterally from the jaw 4 and backing 6 is an extension 7. The extension 7 has in its opposite walls slots 8 in which a clamping block 9 may be inserted. A screw 11 passing through the block 9 may be tightened to press a conductor 12 against the base 13 of the U-shaped body member 1. When it is desired to clamp heavy conductors such as may be used with the present structure but which may be too stiff to be bent and inserted lengthwise under the clamping block and screw, the clamping screw 11 may be partially backed out of the block and the block slid sidewise from the slots 8, the screw 11 passing through an opening 14 connecting with the slot 8. With the clamping block removed the cable may be laid on the base 13 of the U-shaped extension 7.

Referring to the socket structure which comprises the stiff jaw 4 and backing 6 and the insert unit 2 secured to the body backing 6 by screws 18, it can be seen that the insert member comprises a flexible jaw member 16 opposed to the rigid jaw 4 and a backing member 17. A portion 19 of the backing member 17 extends toward the flexible jaw 16 and is spaced from the flexible jaw at its upper end, as is clearly shown in Fig. 2. The spacing between the free end of the jaw member 16 and the backing member 17 is provided so that as a contact blade is inserted between the jaws 4 and 16 it is resisted at first only by the jaw 16 (as shown in Fig. 3), whereafter the free end of the jaw member 16 is swung against the backing member 17 as the blade is inserted further. The backing member thereupon comes into play and in co operation with the jaw member 16 increases the pres sure on the blade B. From the foregoing it is evident that the upper portion 19 of the backing member 17 and the free end of the flexible jaw member 16 come together along opposed flat contact surfaces thus combining the flexible jaw and backing member as joint conducting paths of greater cross section than the flexible jaw alone. When the blade is wholly inserted in the socket (as shown in Fig. 4) electrical current and heat from the meter to which the blade B is attached is conducted both through the rigid heavy jaw 4 and the combination of the flexible jaw 16 and its backing member 17. Both the rigid jaw 4 and the combination of the flexible jaw 16 and backing member 17 afford conducting paths of substantially equal cross section. The electrical current is conducted directly from the rigid jaw 4 to the attached conductor 12 while the heat is dissipated throughout the socket structure, and to a lesser extent through the cable of a conductor 12.

It is apparent that the U shape of the body 1 and its extension 7 provides a structure readily adaptable both to the conductor clamp 9 and to the U-shaped insert unit 2, thus forming a simple rugged structure on which the clamp and insert unit may be mounted.

Shown in Figs. and 6 is another embodiment of the invention in which the present novel socket structure is modified to provide a pivot support for a knife-blade K.

The knife-blade K has a conventional handle H for swinging the blade in and out of contact with a socket of the type shown. This embodiment includes a body 1a having a stiff jaw 4a and opposed backing 6a, and an inverted U-shaped insert 2a in which the jaw leg is directed towards the base 13 of the U-shaped body member. A portion 19a at the lower end of the jaw member 16a extends towards the body backing 6a for engagement therewith when the knife blade is inserted in the support. The knife K is pivotally mounted between the stifl jaw 4n and the flexible jaw 16a by a pivot pin 23 having threads engaging the stiff jaw 4a. The pin passes through a hearing hole 24 in the blade K and a clearance opening 26 in the jaw 16a. The stiff jaw 4a provides a rigid support for the blade and a direct electrical path of large cross section to the clamping block 9 and screw 11, and the flexible jaw insures a constant pressure on the blade while permitting the blade to be swung freely about its pivot.

In the embodiment shown in Fig. 7 the backing member 17 of the insert unit 2 is omitted and a modified flexible jaw 16b engages directly with the body backing 6a of the body member 1a. The flexible jaw 16a is inclined away from the flexible jaw 4a so that the blade may be inserted further into the jaws before the end 1% of the flexible jaw engages the body backing 6a. Adjacent the lower end of the stiff jaw 4a is an upwardly directed abutment 21 pressed in from the wall of the jaw 4a. When the socket is employed in a knife-blade switch structure or is used for receiving the blade of a cartridge type fuse, the abutment 21 limits the extent of entry of the blade into the socket. The abutment 21 may be used with the socket structures shown in Figs. 1 to 4 and particularly in the knife-switch socket shown in Fig. 6. Likewise either the backing member 17 or 17a, or the body backing 6 or 6a, may serve to engage the flexible jaw 16, 16a or 16b as a blade is inserted in the socket, although the backing member 17 or 17a is preferred because of the added resiliency it affords. Thus it will be understood that in each embodiment the socket may comprise a backing member on the insert (17 in Figs. 1 to 4 and 17a in Fig. 5) or a backing member on the body (6 in Figs. 1 to 4 and 6a in Figs. 5 to 7) or both (Figs. 1 to 5).

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claim.

I claim:

A socket for a contact element comprising a rigid U- shaped support and inside the support a flexible U-shaped conductor, the arms of the support and conductor being disposed in the same plane and directed in the same direction, with the outer faces of the conductor arms adjacent the inner faces of the support arms respectively, one arm of the support and the adjacent arm of the conductor having their free end shaped to receive a contact element therebetween and serving as contact arms, the other arm of the conductor being attached to the other arm of the support with its free end bent obliquely from said other arm of the support and extending toward but spaced from the inner face of the contact arm of the conductor, whereby when a contact element is inserted between the contact arms the contact arm of the conductor is flexed inwardly into contact with the other arm of the conductor after which both arms flex together as the element is inserted further.

References Cited in the file of this patent UNITED STATES PATENTS 1,025,245 Cole May 7, 1912 1,231,417 Nero June 26, 1917 1,311,266 Fargo July 29, 1919 1,325,698 Milloy Dec. 23, 1919 1,805,487 Johnson May 19, 1931 2,452,019 Rowe Oct. 19, 1948 2,591,009 Riche Apr. 1, 1952 FOREIGN PATENTS 617,050 Great Britain Jan. 31, 1949 

